DMA_TCDn_BITER_ELINKYES field descriptions (continued)
Field Description
If channel-to-channel linking is enabled (ELINK = 1), then after the minor loop is exhausted, the eDMA
engine initiates a channel service request at the channel defined by this field by setting that channel’s
TCDn_CSR[START] bit.
NOTE:
When the software loads the TCD, this field must be set equal to the corresponding CITER field;
otherwise, a configuration error is reported. As the major iteration count is exhausted, the
contents of this field are reloaded into the CITER field.
BITER Starting major iteration count
As the transfer control descriptor is first loaded by software, this 9-bit (ELINK = 1) or 15-bit (ELINK = 0)
field must be equal to the value in the CITER field. As the major iteration count is exhausted, the contents
of this field are reloaded into the CITER field.
NOTE:
When the software loads the TCD, this field must be set equal to the corresponding CITER field;
otherwise, a configuration error is reported. As the major iteration count is exhausted, the
contents of this field are reloaded into the CITER field. If the channel is configured to execute a
single service request, the initial values of BITER and CITER should be 0x0001.
22.3.36 TCD Beginning Minor Loop Link, Major Loop Count (Channel
Linking Disabled) (DMA_TCDn_BITER_ELINKNO)
If the TCDn_BITER[ELINK] bit is cleared, the TCDn_BITER register is defined as
follows.
Address:
4000_8000h base + 101Eh offset + (32d × i), where i=0d to 15d
Bit 15 14 13 12 11 10 9 8
Read
ELINK BITER
Write
Reset
x* x* x* x* x* x* x* x*
Bit
7 6 5 4 3 2 1 0
Read
BITER
Write
Reset
x* x* x* x* x* x* x* x*
* Notes:
x = Undefined at reset.•
DMA_TCDn_BITER_ELINKNO field descriptions
Field Description
15
ELINK
Enables channel-to-channel linking on minor loop complete
As the channel completes the minor loop, this flag enables the linking to another channel, defined by
BITER[LINKCH]. The link target channel initiates a channel service request via an internal mechanism that
sets the TCDn_CSR[START] bit of the specified channel. If channel linking is disabled, the BITER value
extends to 15 bits in place of a link channel number. If the major loop is exhausted, this link mechanism is
suppressed in favor of the MAJORELINK channel linking.
Table continues on the next page...
Memory map/register definition
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
482 NXP Semiconductors
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